Method for forming sponges



Aug. 16, 1966 J. R. BRYSON 3,266,199

METHOD FOR FORMING SPONGES Original F'iled Oct. 14, 1963 2 h s-Sh 1INVENT OR James R. 57:95am

' MA MW W Wh Aug. 16, 1966 J. R. BRYSON METHOD FOR FORMING SPONGES 2Sheets-Sheet 2 Original Filed Oct. 14, 1965 800905 0F COMPRESSEDINVENTOR James R. Brysam A rfoe/v ys United States Patent 3,266,199METHOD FUR FORMING SPUNGES James R. Bryson, Lutherville, Md, assignor toWashington Ethical Labs, Incorporated, Washington, D.C., a corporationof the District of tColurnbia Original application (let. 1%, 1963, Ser.315,963, now Patent No. 3,228,145, dated .lian. 11, 1966. Divided andthis application July 20, 1965, Ser. No. 482,973 6 Claims. (Cl. 51-323)This application is a division of my copending application Serial No.315,963, filed October 14, 1963, now Patent No. 3,228,145, dated January11, 1966.

This invention relates to a method for forming sponges, and moreparticularly it concerns the formation of small cylindrical sponges ofthe type especially adapted for use in vaginal cleansing instruments.

In Patent No. 3,228,398, dated January 11, 1966, there is disclosed avaginal cleansing instrument in which a cylindrical sponge is mounted onthe end of an elongated plastic handle. The material from which thesponge is made is polyurethane foam and preferably polyesterurethanefoam to provide such physical characteristics as high flexibility,machinability, and a cellular structure which is partially opened andpartially closed. Because of the intended use, it is essential that thecellular structure of the polyurethane foam be presented completelyabout the surface of the sponge. The required surface characteristics,i.e., the natural partially open and partially closed celled structureof the polyurethane foam, together with the rounded end, cylindricalshape of the sponge have led to considerable difficulty in themanufacture of the sponges. For example, the requirement that thecellular structure of the polyurethane be presented at the surface ofthe sponge precludes the use of molding techniques because of theformation of a non-absorbent film on the surface of molded polyurethanefoam. Moreover, the exterior shape of the sponge presents difficulties.In this latter respect, particularly where the sponge is used in avaginal cleansing instrument, it is imperative that the outside surfacethereof be smooth or characterized by continuous curvilinear surfaceswithout any sharp or jagged edges. Accordingly, conventional shapingtechniques used with polyurethane foam are either ineffective in theproduction of the required ultimate shape or require so much care andtime in their execution as to make them impractical.

Accordingly, a principal object of the present invention is to provide anew and unique method for the formation of sponges, particularly spongesused in vaginal cleansing instruments and by which the problemsheretofore experienced in their manufacture are effectively andsubstantially overcome.

A further object of this invention is to provide a method by which theformation of sponges of the type referred to may be effected in aneconomical and yet expeditious manner.

A further object of the present invention is to provide a method for themanufacture of cylindrical sponges useable in vaginal cleansinginstruments which results in the sponge having superior physicalcharacteristics.

In general, the foregoing objectives are accomplished by machining aslab of foam material to remove portions thereof leaving the shapedsponge article remaining. In this manner, the cellular structure on theinterior of the foam slab is presented without change on the surface ofthe article. The machining is carried out by first abrading the endportions of the sponge to be formed about an axis extending across theslab thickness. Hence, a pair of abrading wheels having the desiredsurface characteristics and rotating about the axis of the sponge to beformed may be brought against opposite sides of the 3,26%,l99 PatentedAugust 16, 1966 slab simultaneously. Having thus formed the end portionsof the sponge in the slab of foam material, an annular cut is madeconcentric with the axis of the sponge across the width of the slab.Care is taken to index the annular cutting means with the slab so thatthe cylindrical sides formed by the annular cut are continuous with ortangential to the abraded curved ends. As a further incident to thepresent invention, an axial handle mounting aperture may be formedsimultaneously with the formation of the cylindrical cut by forming anannular cut of smaller diameter also concentric with the axis of thesponge from one end thereof through to a point short of the thickness ofthe slab. In this manner, the aperture will be formed with a tongueextending from its base centrally outwardly to be compressed uponmounting the sponge upon a handle in accordance with the inventiondescribed in accordance with Patent No. 3,228,398. The apparatus forforming the annular cuts is preferably in the form of a cylindricalcutting member having an annular cutting edge on one end and rotatableabout a central axis. The cutting member is movable into the slab offoam, and upon such movement the shaped sponge article will be containedwithin the cylindrical cutting member. To eject the article, compressedair is fed to the interior of the cutting member.

A more complete understanding of the present invention, together withother objects and further scope of applicability may be had from thedetailed description following below, taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a cross-section of the shaped sponge article formed by themethod of this invention;

FIG. 2 is a fragmentary cross-section illustrating one phase of thesponge forming method thereof; and

FIG. 3 is a fragmentary cross-section illustrating a further phase ofthe method thereof.

Referring now to the drawings, and particularly to FIG. 1 thereof, asponge useable with the vaginal cleansing intsrument disclosed in PatentNo. 3,228,398 is illustrated as having a cylindrical body portion 10with inner and outer rounded or substantially semi-spherical ends 12 and14, respectively. As above mentioned, the material from which the spongeis made is polyurethane foam and preferably a polyester-urethane foam.While this material is particularly suitable for use with the instrumentdisclosed in Patent No. 3,228,398, it will be appreciated that themethod of the present invention is applicable to other similarmaterials, A handle mounting aperture 16 extends from the inner end 12to a point along the length of the sponge short of the outer end 14. Theaperture is as shown in the form of an annulus to define a centralprojecting tongue 18. The tongue functions to provide a compressed massof foam material near the: outer end 14 when a handle (not shown) isinserted into the aperture 16, as described in Patent No. 3,228,398.

As shown in FIGS. 2 and 3 of the drawings, the formation of the spongeillustrated in FIG. 1 is carried out by mounting a slab of foammaterial'20 on a carriage 22 having a plurality of apertures 24 onuniformly spaced center lines 26. The apertures 24 are of a diameter tobe somewhat larger than the diameter of the sponges to be formed andalso, the carriage is arranged for movement in the direction of thearrow 28 in increments corresponding precisely to the spacing betweenthe center lines 26.

A pair of working stations are positioned along the length of carriagetravel to operate about fixed axes 3t) and 32 spaced from each other adistance to accommodate precise alignment between the aperture centerlines 26. While it is preferred that the axes 3i and 32 be spaced thesame as the spacing between the aperture center lines 26, it will beappreciated that this spacing may be a multiple of the spacing betweenthe center lines 26. Thus, by means of a detent arrangement (not shown)the carriage may be brought to rest after each increment of travel sothat the center lines 26 of the aperture become successively alignedwith the station center lines or axes 3t) and 32, respectively.

At the station defined by the axis 30, a sponge end forming apparatus ispositioned and as shown in FIG. 2, this apparatus includes a pair ofcupshaped abrading elements 34 and 36 having concave, semi-sphericalabrading surfaces 38 and 40. The abrading surfaces, as shown, areintegral with the elements 34 and 36 but it is contemplated that thesurfaces 38 and 44 in some applications, may be abrasive metalparticles, emery cloth, sandpaper and the like secured such as by anadhesive to the elements 34 and 36. Also, although the semi-sphericalshape of the surfaces 38 and 40 is preferred "because of the intendeduse of the sponges to be formed, other shapes defined by surfaces ofrevolution may be employed. Each of the abrading elements is journaledfor rotation about the axis 30 in a support 42 movable in the directionof arrows 44 for reciprocation along the axis Stl. Pulleys 46 areprovided by which torque may be transmitted to drive the elements 34 and36.

At the station defined by the axis 32, a rotatable cutting toolgenerally designated by the reference number 48 is positioned. Thecutting tool includes an outer cylindrical cutting member 50 having acutting edge 52 On the lower end thereof and an inner cylindricalcutting member 54 having a cutting edge 56 also on its lower end. Thecutter members 549 and 54 may be of any suitable metal capable ofwithstanding the heat involved in cutting the foam material and arepreferably formed with serrations 58 and 59, respectively, at spacedintervals determined by speed, material and size of cut diameter toprovide a clean smooth cut. The cutter members 50 and 54 are bothsupported on a common hub 60 journalcd for rotation about the axis 32 ina supporting frame 62 reciprocable inthe direction of the arrow 64 by anamount sufiicient so that the cutting edge 52 may be moved through thethickness of the slab 20. A pulley 66 is provided to transmit arotational driving torque to the hub 60 and thus to the cutter members tand 54. Although the manner in which the cutter members are mounted onthe hub may vary in practice, it is essential that they be mounted sothat the annulus between the two cutter members is essentially smooth.Hence, the outer cutter member 59 is press fit over an undercut portion68 of the hub 66 whereas the inner cutter member 54 is press fit on anaxial extension 70 of the hub.

To eject the sponge from the cutting tool 48 and as well to effect ameasure of cooling, the hub is formed with air passages 72 incommunication with a chamber 74 in the support 62 by way of radial ports76. The chamber, in turn, is supplied with compressed air from asuitable source designated at 78 by way of a flexible conduit 80 havinga valve 82.

The manner in which the apparatus described above operates to carry outthe method of the present invention may now be understood. With the slabpositioned on the ca rriage 22, the abrading elements 34 and 36 afterachieving rotational speed are brought against opposite surfaces of theslab along the axis to form the semispherical convex end configurationsof the sponge. Thereafter, the elements are withdrawn and the carriage smoved until the partially formed portion of the slab is aligned with theaxis 32. At this point, the cutter member 48 having been rotating at theproper rotational velocrty is lowered to form inner and outer annularcuts by means of the inner and outer cutter members 54 and 50,respectively. The diameter of the cutting edge 52 is selected so thatthe foam material is cut on a cylinder meeting the semi-spherical endportions formed by the abrading elements 34 and 36 precisely at atangent of the curved end portion. In this manner, a smooth continuouslycurvilinear external surface is formed on the (i sponge. Also, the innercutter member 54 will operate to form the handle mounting aperture 16 inthe sponge, together with the extending tongue 18 shown in FIG. 1.

When the cutter 48 has fully penetrated the slab 2t and thus completedthe formation of the sponge, the sponge will be lodged in the annulusbetween the inner and outer cutter members. At that point, the valve 82will he opened to permit compressed air to flow into the upper portionof the annulus and eject the completed sponge downwardly through theaperture 24 whose center line 26 is aligned with the axis 32. Then,after the cutter 48 has been raised clear of the slab 24, the carriageis moved through another increment of distance and the cycle repeated.it Will be understood that the abrading elements 34 and 36 will beoperated concurrently with the cutter 43, the abrading elementsoperating about the axis 30 at the first station simultaneously as thecutter element operates to form the cylindrical body portion of thesponges at the station defined by the axis 32.

Thus, it will be appreciated that the present invention affords anextremely effective method for the formation of sponges from slabs offoam material and by which the above mentioned objectives are fullyachieved. Also, it will be appreciated that while the method of thisinvention has been described as having particularly utility with respectto the manufacture of sponges of the type used in vaginal cleansinginstruments, it will be apparent that the invention will haveapplicability in other fields. Also, since many modifications andvariations in the invention are possible, it is to be distinctly thatthe foregoing description is illustrative only, not limiting, and thatthe true spirit and scope of the present invention is to be determinedby reference to the appended claims.

The invention claimed is:

1. The method of forming a cylindrical sponge having rounded portions atboth ends comprising the steps of machining opposite sides of a slab offoam material about the axis of the sponge to form the rounded endportions, and making an annular cut through the slab with an annularcutting edge rotating about the axis of the sponge.

2. The method of forming a cylindrical sponge to be mounted on a handlefor use as a vaginal cleanser, said method comprising the steps of:abrading opposite sides of a slab of foam material to form convexportions about an axis extending across the thickness of said slab,making an inner annular cut concentric with said axis from one side ofsaid slab to a point short of the other side thereof to form a handleaperture having a tongue projecting centrally from its base, and makingan outer annular cut also concentric about said axis and throughout thethickness of said slab.

3. The method of forming a cylindrical sponge having at least one shapedend portion from a slab of foam material having a thickness at leastequal to the length of sponge to be formed comprising the steps of:indexing said slab relative to a first axis to align said first axiswith the axis of the sponge to be formed, said axes extending in thedirection of slab thickness, machining at least one side of said slababout said first axis to form said shaped end portion, indexing saidslab to align the axis of the sponge to be formed with a second axisspaced from said first axis, and making an annular cut concentric withsaid second axis through said slab to separate the sponge from saidslab.

4. The method of forming a cylindrical sponge having semi-sphericalshaped end portions from a slab of foam material having a thickness atleast equal to the length of sponge to be formed comprising the stepsof: indexing said slab relative to a first fixed axis to align saidfirst axis with the axis of the sponge to be formed, said axes extendingin the direction of slab thickness, machining opposite sides of saidslab about said first axis to form said semi-spherical end portions,indexing said slab to align the axis of the sponge to be formed with asecond fixed axis, and making an annular cut concentric with ReferencesCited by the Examiner UNITED STATES PATENTS Harrison et a1. 77-69 XWatson 2- 77-69 X Mulholland 51-80 Griswold 51-46 1 011. et a1. 146-236Marcerou 77-69 X Scholl 51-281 X LESTER M. SWINGLE, Primary Examiner.

1. THE METHOD OF FORMING A CYLINDRICAL SPONGE HAVING ROUNDED PORTIONS ATBOTH ENDS COMPRISING THE STEPS OF MACHINING OPPOSITE SIDES OF A SLAB OFFOAM MATERIAL ABOUT THE AXIS OF THE SPONGE TO FORM THE ROUNDED ENDPORTIONS, AND MAKING AN ANNULAR CUT THROUGH THE SLAB WITH AN ANNULARCUTTING EDGE ROTATING ABOUT THE AXIS OF THE SPONGE.